When USC's first team took the field Wednesday - three days before the season opens against Idaho - the offensive line had one starter in place from its projected lineup entering fall camp. And that guy has a cracked rib.

Senior center Matt Spanos tore his right triceps Tuesday, and he is out at least a few weeks. Left guard Jeff Byers moved to center, and senior Alatini Malu took his former spot. Redshirt freshman Zack Heberer was at right guard, standing in for Chilo Rachal, who bruised the back of his right knee Tuesday.

Charles Brown won the starting right tackle job - with Drew Radovich sidelined by a back injury for much of fall camp - and Sam Baker, with his injured rib, was protecting John David Booty's blind side.

The one alteration expected to Wednesday's lineup is that Rachal should return.

"It's nothing really major," the junior said of his injury. "I'm playing for sure."

Byers arrived at USC in 2004, as the top-ranked center in his national recruiting class. But Ryan Kalil beat him out for the starting job, while Byers had trouble snapping the ball. That year, he started four late-season games at left guard, but he has been sidelined for most of the past two seasons, with back and hip injuries.